Process of converting hydrocarbons into lower-boiling products



Dec; 4, 1928 F. A. HOWARD PROCESS CONVERTING HYDROCARBONS INTO LOWERBOILING PRODUCTS Filed May 21, 1923 HEATKNG c u, I

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Ls tv CKUDEIKEJ'IDUUM "K THELIKE Patented Dec. 4, 1928.

UNITED STATES; PATENT OFFICE.

I FRANK A. HOWARD, OF ELIZABETH, NEW JERSEY, ASSIGNOIt TO STANDARD OILDE- VELOPMENT COMPANY, A CORPORATION OF DELAWARE.

PROCESS OF CONVERTING HYDROCARBONS INTO LOWER-BOILING PRODUCTS.

Application filed May 21,

This invention relates to the art of pyrolytic conversion ofhydrocarbons to lower boiling products and will be fully understood fromthe following description, reference being had also to the accompanyingdrawing which represents diagrammatically one form of apparatus by whichthe invention may be practiced. I

'In the drawing, the reference character A designates a heated conduitor passageway of suitable construction, for example a bank of tubesconnected at the ends by cross-over connections from tube to tube androw to row to allow flow of fluid in a consecutive path and arranged tobe heated, as for example by a furnace. Connected to the firstpassageway by'a pipe 1 is a further passageway, which may be constructedalong similar lines or as an enlarged passageway or drum B as moreparticularly illustrated, and in any case guarded against heat loss, asby being covered I with insulation or mounted so as to be bathed by hotgases, as preferred. From the passageway B a connection 2 preferablyhaving a pressure-release valve 3, leads to a vapor separator C, and avapor line 4 from thence passes to'suitable condensing means. A tardraw-off 5 is provided at the bottom of. the vapor separator and alateral line 6 for heavy condensate where such is collected from thevapors rising in the vapor separator.

A pipe 7 from a source of oil supply 8 connects into the heatingconduit'A, and a pipe 9 from a source of supply 10 connects into thepassageway B, and either or both of the lines as desired'may beconnected through heat exchangers for preliminary heating of the stocks;veniently for instance, heat exchangers o he vapors disengaged at thevapor separator being employed.

Oil-is fed from the source ofsupply 8 into the heating conduit or coilA, and it is preferable here to feed a relatively clean oil,

with-a minimum formation of carbon. Such an. oil may be for instance akerosene or a light gas oil, and with such a very high coil outlettemperature, for example around 9001000 F may be employed. Through thepipe 9 the passageway B may be fed also with a relatively dirty stock,or stock of relatively greater coke-forming tendencies; for example acrude residuum, high in asphaltic bodies or wax or both, or a heavy thatis, an oil which willcompletely vaporize 1923. Serial No. 640,491.

distillate may be used, such as parafline slop or heavy gas oil. Anadvantageouscombr nation is light gas oil in the heating zone A withheavy gas oil introduced into the second zone B.

In such manner the heating zone A may be operated relatively cleanly andheat carried by the products passing on to the next zone B may ther'eaid in the conversion under pressure of additional amounts ofhydrocarbons of different character as desired, and particularlyresiduumor heavy distillate stocks having considerable coke-forming tendency.

While I prefer to operate the heating zone so as'to secure aconsiderable portion of the cracking therein the hydrocarbons being alsosubstantially completely in vaporous condition, and then finish in thesecond zone using the heat already acquired to also crack additionallyintroduced stocks of different character, in its broader aspects myinvention also contemplates'operating while adding the different stockin the second zone, irrespective of how much or how little thehydrocarbons may be in vaporous condition and irrespective of how thecracking is divided between the two zones.

What I claim is 1. A process for the conversion of hydrocarbons'intolower boiling products which comprises feeding a stream of light gas oilinto a heating passageway at a temperature around 9001000 F., to effecta material amount of cracking in vaporous condition,

allowing conversion substantially in the liquid phase, to go on in themixture solely on the heat already acquired, and passing the. liquidproducts together with any vapors, from a point substantially above thebottom of the passageway guarded again st heat loss into avapor-separating zone and separating the lighter hydrocarbons from theheavier.

2. A process for the conversion of hydrocarbons into lower boilingproducts, which comprises passing a stream of hydrocarbons ofsubstantially completely vaporized character through a heatingpassageway-at a temperature around 9001000 F. to efiect a materialamount of cracking in vaporous condition, then passing the products intoa furthe Inn passageway which is guarded against heat loss, while alsointroducing a hydrocarbon stock having greater coke-forming tendency,contacting said vapor and liquid products to- 5 gether for a substantialperiod of time allowing conversion substantially in the liquid phase togo on in the mixture solely on the heat already acquired, and passingthe liquid products, together with any vapors, from a point substantiallabove the bottom of the passageway guar ed against heat loss into avapor-separatin zone and separating the lighter hydrocar ons from theheavier.

FRANK A. HOWARD.

